1. Related Field
The present invention relates to a coupling arrangement according to the preamble of the independent patent claim 1.
Accordingly, the invention in particular relates to a coupling arrangement for the front of a tracked vehicle, in particular a rail vehicle, wherein the coupling arrangement comprises a central buffer coupling having a gladhand, a coupling shaft supporting the gladhand and a bearing via which the coupling shaft can be joined with the undercarriage of the vehicle pivotable in horizontal and/or vertical direction, and wherein the coupling arrangement furthermore comprises an energy consuming device allocated to the central buffer coupling having at least one energy consuming element with a destructive design. In so doing, it is in particular provided that the energy consuming element is designed such that it responds when a critical impact force defined in advance applied to the gladhand is exceeded and that it releases at least part of the energy generated in connection with the transmission of the impact force and introduced into the energy consuming device via the coupling shaft via plastic deformation with the simultaneous longitudinal motion of the central buffer coupling relative to the undercarriage of the vehicle.
2. Related Art
The principal of the present type of coupling arrangement may be generally understood from the prior art. In rail vehicle technology, it serves, for instance, the purpose of joining the freight car body of a vehicle with an adjacent freight car body.
Moreover, with respect to rail vehicle technology, it has been disclosed to provide a shock absorber at the front side of a freight car body, which commonly consists of a combination of an absorbing device, for example in the form of a spring-loaded apparatus, and an energy consuming device. The purpose of the absorbing device is to absorb the tractive and impact forces occurring in regular driving mode and transmitted between two adjacent freight car bodies via the central buffer coupling. In contrast, the purpose of the energy absorbing device is to also protect the vehicle in particular in connection with higher collision speeds.
In so doing, it is normally provided that the absorbing device absorbs a defined scope of tractive and impact forces, while passing on forces beyond this scope to the undercarriage of the vehicle. As a result, tractive and impact forces which occur, for instance, between the individual freight car bodies of a multiple-unit rail vehicle during regular driving mode are absorbed by this absorbing device which normally has a regenerative design.
In contrast, if the operational load of the absorbing device is exceeded, such as if the vehicle hits an obstacle or if the vehicle is abruptly slowed down, there is a risk that the interface between the adjacent freight car bodies, in particular the absorbing device and the possibly provided link or coupling joint between the individual freight car bodies, may potentially get destroyed or damaged. In any case, the absorbing device is inadequate to absorb the overall accumulated energy. As a result, the absorbing device is then no longer incorporated in the energy consuming concept of the entire vehicle.
In order to prevent the accumulated impact energy from being transmitted directly onto the undercarriage of the vehicle in said crash scenario, it is known from rail vehicle technology to connect an energy consuming device downstream of the absorbing device. The corresponding energy consuming device connected downstream normally responds as soon as the operating load of the absorbing device is exceeded and serves the purpose of consuming accumulated impact energy at least partially, i.e., to convert it, for instance, into thermal energy and unit resilience. The provision of said type of energy consuming device is generally recommendable for reasons of derailing safety, in order to prevent the impact energy accumulated in case of a crash from being transmitted directly onto the undercarriage of the vehicle, and in particular to prevent the undercarriage of the vehicle from being exposed to extreme stress and from possibly being damaged or even destroyed.
To protect the undercarriage of the vehicle from being damaged in connection with strong collision impacts, an energy consuming device having an energy consuming element with a destructive design is often used as so-called “shock absorber,” designed, for example, in such a way that it responds as soon as the working consumption of the absorbing device is exhausted and that it at least partially absorbs and releases the energy transmitted via the energy consuming element as a result of the power flux. The energy consuming element can in particular be a deformation tube with which the impact energy introduced into the energy consuming device is converted into unit resilience and heat by way of (intended) plastic deformation in a destructive manner after a critical impact force has been exceeded.
A coupling arrangement comprising a central buffer coupling, a bearing bracket and an energy consuming device connected downstream of the bearing bracket is disclosed, for example, in the printed document DE 43 02 444 A1. The central buffer coupling comprises a gladhand as well as a coupling shaft supporting the gladhand in which an absorbing device for absorbing the tractive and impact forces occurring in regular driving mode and introduced into the gladhand is integrated. The end section of the coupling shaft on the vehicle side is flexibly retained in the bearing bracket joined with the undercarriage of the vehicle. A deformation tube is used as energy consuming device for the coupling arrangement disclosed in the prior art, which is resting on the bearing bracket of the coupling arrangement and is designed such that it responds when the operating load of the absorbing device integrated in the coupling shaft is exceeded and is pushed through a nozzle plate resting on the end section of the deformation tube on the vehicle side via axial shifting of the bearing bracket under the reduction of the cross-section.
On the one hand, the disadvantage of said solution is that a relatively large space is required in the undercarriage of the freight car body for the reverse motion of the bearing bracket together with the deformation tube, because the deformation tube is pushed through the nozzle plate into an additionally required space behind the coupling arrangement when the deformation tube is deformed, i.e., when the energy consuming device responds. For coupling arrangements in which said additional space is not available, for instance because of the immediate vicinity of a bogie, it will not be possible to use the solution for the energy consuming device proposed in said prior art.
However, the solution disclosed in the printed document DE 43 02 444 A1 is in particular associated with the risk that the deformation tube, for example in the cone-shaped bore hole formed in the nozzle plate, tends to “seize up” or become wedged when the energy consuming device responds—especially in connection with a vertical or inclined load of the deformation tube, such that the function of a destructive energy consumption is no longer given.
More broadly speaking, the known energy consuming devices, such as ones described above, are associated with the basic risk that components which shift relative to the undercarriage of the vehicle in the direction of the vehicle in case of a crash jam during said axial displacement, whereby the achievable energy consumption is indefinite and in particular no previously definable course of events is given in connection with the energy consumption. In detail, the risk associated with the solution described in DE 43 02 444 A1 is that the deformation tube itself, which is axially displaced toward the vehicle or freight car body together with part of the bearing bracket in this solution, becomes wedged or jammed or seizes up in the opening provided in the nozzle plate in case of a crash.